Приведем одночлены к стандартному виду:
\[ a^2 + 2ab + b^2 \]
Приведем подобные:
\[ (a+b)^2 \]
\[ (m-n)(m+n) = m^2 - n^2 \]
\[ (x-2)(x+2) = x^2 - 4 \]
\[ (a+s)(a-s) = a^2 - s^2 \]
\[ (b+4)(b-4) = b^2 - 16 \]
\[ (2x-3t)(2x+3t) = 4x^2 - 9t^2 \]
\[ (0.2a-1.2b)(0.2a+1.2b) = 0.04a^2 - 1.44b^2 \]
\[ (\frac{2}{3}m-\frac{1}{7}n)(\frac{2}{3}m+\frac{1}{7}n) = \frac{4}{9}m^2 - \frac{1}{49}n^2 \]
\[ 5x(x - y)(x + y) = 5x(\mathbf{x^2 - y^2}) = 5x^3 - 5xy^2 \]
\[ 2z(z - t)(z + t) = 2z(z^2 - t^2) = 2z^3 - 2zt^2 \]
\[ 19 \cdot 21 = (20-1)(20+1) = 20^2 - 1^2 = 400 -1 = 399 \]
\[ 29 \cdot 31 = (30-1)(30+1) = 30^2 - 1^2 = 900 - 1 = 899 \]
\[ 99 \cdot 101 = (100-1)(100+1) = 100^2 - 1^2 = 10000 - 1 = 9999 \]
\[ 46 \cdot 54 = (50-4)(50+4) = 50^2 - 4^2 = 2500 - 16 = 2484 \]
\[ 195 \cdot 205 = (200-5)(200+5) = 200^2 - 5^2 = 40000 - 25 = 39975 \]
\[ 33 \cdot 47 = (40-7)(40+7) = 40^2 - 7^2 = 1600 - 49 = 1551 \]
\[ (-b^2+5)(5 + b^2) = (5-b^2)(5 + b^2) = 25 - b^4 \]
\[ (-5+n)(n-5) = (n-5)(n-5) = n^2 - 10n + 25 \]
\[ 5(x-7)(x+7) = 5(x^2 - 49) = 5x^2 - 245 \]
\[ (x^2 +36)(-6 + x)(6 + x) = (x^2 + 36)(x^2 - 36) = x^4 - 1296 \]
\[ (\mathbf{p^2} - 2x)(\mathbf{p^2} + 2x) = p^4 - 4x^2 \]
\[ (2z - \mathbf{3x})(2z + \mathbf{3x}) = 4z^2 - 9x^2 \]